JP2023005633A - Sheet processing device and image formation system - Google Patents

Abstract

To provide a sheet folding device which can stably guide one end of a sheet that is applied with folding processing and is switchback-conveyed to a side where the other end of the sheet is located by a guide member.SOLUTION: A sheet processing device B comprises a pressing guide member 30 which is brought into contact with a sheet that is applied with folding processing in a sheet conveyance path 20 and is switchback-conveyed by a nip part 22c, guides one end of the sheet to a side where the other end of the sheet is located in the sheet conveyance path 20, can rotate between a retreat position and a guide position, enters a region between the rotation locus of a first roller surface 22a2 and the rotation locus of a second roller surface 22a3 of a folding roller 22a when rotating from the retreat position to the guide position, and is brought into contact with the sheet at the guide position located outside the region.SELECTED DRAWING: Figure 13

Description

The present invention relates to, for example, a sheet processing apparatus that folds a sheet sent from an image forming apparatus, and an image forming system that includes the image forming apparatus and the sheet processing apparatus.

Conventionally, a sheet processing apparatus for folding a bundle of sheets into a booklet has been provided as an apparatus for post-processing sheets discharged from image forming apparatuses such as copiers, printers, facsimiles, and multifunction devices thereof. As a sheet processing apparatus, for example, a sheet conveyed from an image forming apparatus to a stacker is pushed at a predetermined position with a thrust plate and pushed into a nip portion of a pair of folding rollers, and the sheet is nipped by the pair of folding rollers to perform folding processing. It has been known.

Further, Japanese Patent Application Laid-Open No. 2002-200002 describes a sheet processing apparatus that performs the above-described folding process on two different portions of a sheet and folds the sheet so that one end of the sheet is on the inner side of the folded sheet. . In the sheet processing apparatus disclosed in Japanese Patent Laid-Open No. 2004-100000, a sheet that has undergone the first folding process is switchback-conveyed and returned to the stacker, and the second folding process is performed on the sheet at a position different from that of the first folding process, thereby folding the sheet into three inwards. conduct.

Further, in Patent Document 1, a turn-over prevention member ( A configuration in which a guide member) is provided is described. By providing the turn-over prevention member in this way, when the sheet is switchback-conveyed during the inward tri-folding process, one end of the sheet moves to the side opposite to the side where the other end of the sheet is located, and the sheet is turned over. It is suppressed to be returned to the stacker in the state.

JP 2012-56674 A

In the configuration disclosed in Patent Document 1, when the anti-turnover member is in contact with the sheet at a position away from the nip portion of the folding roller pair, the distance from the nip portion to the anti-turnover member is increased, and the sheet is transported to the anti-turnover member. It takes a long time to be transported to the anti-turning member. For this reason, the return of the folded portion of the sheet becomes large until the sheet comes into contact with the turn-up prevention member, and the sheet does not contact the turn-up prevention member well, and the sheet does not reach the desired position. There is a risk that you will not be guided to

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a sheet folding device that can stably guide one end of a sheet that has undergone a folding process and is being switchback-conveyed to the side where the other end of the sheet is positioned by a guide member. With the goal.

A representative configuration of the present invention for achieving the above object is a sheet processing apparatus for folding sheets, which includes a conveying path having a guide surface for guiding the conveyed sheet and a constant radius to the peripheral surface. a first rotating body having a certain first peripheral surface and a second peripheral surface having a radius smaller than the radius of the first peripheral surface; rotating in synchronization with the first rotating body; A second rotating body that presses against the first peripheral surface of the body to form a nip portion, wherein the sheet conveyed to the conveying path during the folding process is rotated while being nipped by the nip portion. is conveyed in the first direction to perform the folding process, and the folded sheet is rotated while being nipped by the nip portion, thereby switching back to the second direction opposite to the first direction. and a second rotating body that is conveyed by a second rotary body that contacts the sheet that has undergone the folding process in the conveying path and is moved in the second direction by the nip portion, and that one end portion of the sheet is held in the conveying path. a first position, which is a guide member that guides the sheet to the side where the other end portion of the sheet is located, and is a position that is substantially the same as the guide surface or a position that is retreated from the conveying path relative to the guide surface; and a second position in contact with the sheet in the conveying path, and when rotating from the first position to the second position, the rotation trajectory of the first peripheral surface and the second position. a guide member that enters into a region between the peripheral surface and the locus of rotation, and abuts against the sheet at the second position located outside the region.

According to the present invention, in the sheet folding device, one end portion of the sheet that has undergone the folding process and is being switchback-conveyed can be stably guided by the guide member to the side where the other end portion of the sheet is positioned.

1 is an explanatory diagram of an overall configuration of an image forming system; FIG. 1 is an explanatory diagram of an overall configuration of a sheet processing apparatus in an image forming system; FIG. 2 is a cross-sectional view showing a folding device of the sheet processing apparatus; FIG. 1 is a plan view showing a sheet folding device; FIG. FIG. 10 is a cross-sectional explanatory view of an operation of folding a sheet into three. FIG. 10 is a cross-sectional explanatory view of an operation of folding a sheet into three. FIG. 10 is a cross-sectional explanatory view of an operation of folding a sheet into three. FIG. 10 is a cross-sectional explanatory view of an operation of folding a sheet into three. FIG. 10 is a cross-sectional explanatory view of an operation of folding a sheet into three. FIG. 10 is a cross-sectional explanatory view of an operation of folding a sheet into three. FIG. 10 is a cross-sectional explanatory view of an operation of folding a sheet into three. 1 is a partial perspective view of a sheet folding device; FIG. FIG. 4 is an explanatory diagram of the arrangement of a pair of folding rollers, a folding blade, and a pressing guide member; FIG. 10 is an operation explanatory view of a pressing guide member; FIG. 5 is a cross-sectional explanatory view of the operation of the folding blade and the blade guide member; FIG. 5 is a cross-sectional explanatory view of the operation of the folding blade and the blade guide member; FIG. 5 is a cross-sectional explanatory view of the operation of the folding blade and the blade guide member; FIG. 5 is a cross-sectional explanatory view of the operation of the folding blade and the blade guide member; FIG. 5 is a cross-sectional explanatory view of the operation of the folding blade and the blade guide member; FIG. 3 is a control block diagram of a folding operation in the sheet folding processing apparatus; 4 is a flow chart of folding operation in the sheet folding processing apparatus. 4 is a flow chart of folding operation in the sheet folding processing apparatus. FIG. 4 is a perspective view around a pressing guide member in the folding device; 4 is a schematic cross-sectional view of a pair of folding rollers and a pressing guide member; FIG. 4 is a flowchart of initialization control; 4 is a flowchart of initialization control; FIG. 10 is an explanatory view of operations of a pair of folding rollers and a pressing guide member in initialization control; FIG. 10 is an explanatory view of operations of a pair of folding rollers and a pressing guide member in initialization control;

Next, a sheet processing apparatus according to a preferred embodiment of the present invention and an image forming system having the same will be described with reference to the drawings. FIG. 1 schematically shows the overall configuration of an image forming system equipped with a sheet processing apparatus according to an embodiment of the invention. As shown in the figure, the image forming system 100 includes an image forming apparatus A and a sheet processing apparatus B provided side by side.

<Overall Configuration of Image Forming Apparatus>
The image forming apparatus A is composed of an image forming unit A1, a scanner unit A2 and a feeder unit A3. The image forming unit A1 includes a paper feeding section 2, an image forming section 3, a paper discharging section 4, and a data processing section 5 inside an apparatus housing 1. As shown in FIG.

The sheet feeding unit 2 is composed of a plurality of cassette mechanisms 2a, 2b, and 2c that store sheets for image formation of different sizes, respectively. . Each of the cassette mechanisms 2a, 2b, and 2c is installed detachably from the paper feeding unit 2, and incorporates a separation mechanism for separating sheets one by one and a paper feeding mechanism for feeding out the sheets. The paper feed path 2f is provided with transport rollers for feeding the sheets supplied from the respective cassette mechanisms 2a, 2b, and 2c to the downstream side, and a registration roller pair for aligning the leading edges of the sheets at the end of the path. ing.

A large-capacity cassette 2d and a manual feed tray 2e are connected to the paper feed path 2f. The large-capacity cassette 2d is composed of an option unit that stores sheets of a size that are consumed in large quantities. The manual feed tray 2e is configured to be able to supply special sheets such as thick paper sheets, coating sheets, and film sheets that are difficult to separate and feed.

The image forming unit 3 is configured using an electrophotographic method in this embodiment, and includes a rotating photosensitive drum 3a, a light emitting device 3b for emitting an optical beam, a developing device 3c, and a cleaner ( not shown). The illustrated one is a monochrome printing mechanism, in which a photosensitive drum 3a whose circumferential surface is uniformly charged is irradiated with light according to an image signal from a light emitting device 3b to optically form a latent image, which is then developed. A toner image is formed by depositing toner with the device 3c.

The sheet is sent to the image forming section 3 from the paper feed path 2f in synchronization with the timing of image formation on the photosensitive drum 3a, and the toner image formed on the photosensitive drum 3a is transferred onto the sheet by applying a transfer bias from the transfer charger 3d. to be transcribed. The sheet on which the toner image has been transferred is heated and pressurized when passing through the fixing device 6 to fix the toner image, discharged from the discharge port 4b by the discharge roller 4a, and sent to the sheet processing apparatus B, which will be described later. be transported.

The scanner unit A2 includes a platen 7a on which an image original is placed, a carriage 7b that reciprocates along the platen 7a, photoelectric conversion means 7c, and photoelectric conversion of light reflected from the original on the platen 7a by the carriage 7b. and a reducing optical system 7d guiding to means 7c. The photoelectric conversion means 7c photoelectrically converts the optical output from the reduction optical system 7d into image data, and outputs the image data to the image forming section 3 as an electric signal.

The scanner unit A2 also has a traveling platen 7e for reading the sheet fed from the feeder unit A3. The feeder unit A3 has a paper feed tray 8a for stacking document sheets, a paper feed path 8b for guiding the document sheets fed from the paper feed tray 8a to the traveling platen 7e, and stores the document sheets passing through the traveling platen 7e. It is composed of the discharge tray 8c. A document sheet from the paper feed tray 8a is read by the carriage 7b and the reduction optical system 7d when passing the traveling platen 7e.

<Overall Configuration of Sheet Processing Apparatus>
Next, the overall configuration of the sheet processing apparatus B for post-processing sheets sent from the image forming apparatus A will be described.

FIG. 2 is an explanatory diagram of the configuration of the sheet processing apparatus B according to this embodiment. The sheet processing apparatus B includes an apparatus housing 11 provided with a loading port 10 for introducing sheets from the image forming apparatus A. As shown in FIG. The apparatus housing 11 is arranged in alignment with the apparatus housing 1 of the image forming apparatus A so that the carry-in port 10 communicates with the sheet discharge port 4b of the image forming apparatus A. As shown in FIG.

The sheet processing apparatus B includes a sheet carry-in path 12 that conveys sheets introduced from a carry-in port 10, and a first sheet discharge path 13a, a second sheet discharge path 13b, and a third sheet discharge path branched from the sheet carry-in path 12. 13c, first path switching means 14a, and second path switching means 14b. The first path switching means 14a and the second path switching means 14b are each composed of a flapper guide for changing the transport direction of the sheet transported on the sheet carry-in path 12. As shown in FIG.

The first path switching means 14a is in a mode in which a driving means (not shown) guides the sheet from the carry-in port 10 in the direction of the first discharge path 13a that conveys the sheet in the horizontal direction and the second discharge path 13b that conveys it downward. , and a mode for guiding the sheet to the third sheet discharge path 13c that conveys the sheet upward. The first paper discharge path 13a and the second paper discharge path 13b can reverse the conveying direction of the sheet once introduced to the first paper discharge path 13a and switch back and convey it to the second paper discharge path 13b. It communicates like

The second path switching means 14b is arranged on the downstream side of the first path switching means 14a with respect to the conveying direction of the sheet conveyed through the sheet carry-in path 12. As shown in FIG. The second path switching means 14b has a mode in which a sheet passing through the first path switching means 14a is introduced into the first discharge path 13a by a driving means (not shown), and a mode in which the sheet once introduced into the first discharge path 13a is switched. is switched back to the second discharge path 13b.

The sheet processing apparatus B includes a first processing section B1, a second processing section B2, and a third processing section B3 that perform different post-processing. Further, a punch unit 15 for punching holes in the sheet that has been carried in is arranged in the sheet carrying-in path 12 .

The first processing unit B1 accumulates and collates a plurality of sheets discharged from the discharge port 16a at the downstream end of the first discharge path 13a with respect to the conveying direction of the sheets conveyed on the sheet carry-in path 12. It is a binding processing unit that performs binding processing and discharges onto a stacking tray 16 b provided outside the device housing 11 . The first processing section B1 also includes a sheet conveying device 16c that conveys sheets or a sheet bundle, and a binding processing unit 16d that binds the sheet bundle. A discharge roller pair 16e is provided at the downstream end of the first discharge path 13a to discharge the sheet from the discharge port 16a and to switch back and convey the sheet from the first discharge path 13a to the second discharge path 13b. It is

The second processing section B2 is a folding processing section that folds a plurality of sheets that are switchback-conveyed from the second discharge path 13b into a sheet bundle, binds the sheet bundle, and then folds the sheet bundle. As will be described later, the second processing section B2 includes a folding processing device F that folds a sheet or a bundle of sheets carried in, and a folding processing device F that folds a sheet conveyed to the second discharge path 13b along the sheet conveying direction. A binding processing unit 17a is provided immediately upstream of the apparatus F to bind the sheet bundle. The folded sheet bundle is discharged onto a stacking tray 17c provided outside the apparatus housing 11 by a discharge roller 17b.

The third processing section B3 divides the sheets sent from the third discharge path 13c into a group in which the sheets are stacked with a predetermined amount of offset in the sheet width direction perpendicular to the conveying direction, and a group in which the sheets are stacked without being offset. Perform jog sorting. The jog-sorted sheets are discharged to a stacking tray 18 provided outside the device housing 11, and offset sheet bundles and non-offset sheet bundles are stacked.

FIG. 3 schematically shows the overall configuration of the second processing section B2. As described above, the second processing section B2 includes the folding processing device F that folds the bundle of sheets that has been transported from the second discharge path 13b and has been stacked and collated, and the binding processing of the bundle of sheets that has not undergone the folding processing. and a binding processing unit 17a. The illustrated binding processing unit 17a is a stapler device that binds a sheet bundle by driving staples.

A sheet conveying path 20 is connected to the second discharge path 13b in order to carry the sheet into the folding device F. As shown in FIG. With respect to the conveying direction of the sheet conveyed to the sheet stacking tray 21 from the second discharge path 13b, the sheet stacking tray 21 forming a part of the sheet conveying path 20 performs folding processing on the downstream side of the sheet conveying path 20. It is provided for positioning and stacking sheets. Immediately upstream of the sheet stacking tray 21, the binding processing unit 17a and its staple receiving portion 17d are provided at opposite positions with the sheet conveying path 20 interposed therebetween.

On one side of the sheet stacking tray 21, a pair of folding rollers 22 as a pair of folding rollers are arranged so as to face one side of the sheet or sheet bundle stacked on the sheet stacking tray. The folding roller pair 22 is composed of a pair of folding rollers 22a and 22b whose roller surfaces are brought into pressure contact with each other, and a nip portion 22c, which is the pressure contact portion, is arranged facing the sheet stacking tray 21. As shown in FIG. The folding rollers 22a and 22b are arranged such that the intervals between the folding rollers 22a and 22b and the sheet stacking tray 21 are substantially the same on the upstream side and the downstream side along the carrying direction of the sheet carried into the sheet stacking tray 21 from the upper upstream side to the lower downstream side. are arranged side by side. The folding rollers 22a and 22b are continuous rollers whose surfaces that contact the sheet are not divided into a plurality of parts in the direction of the rotation axis. In the present invention, the rotating portion of the pair of folding rotating members is not limited to the folding rollers 22a and 22b of the present embodiment, and can be configured by a rotating belt or the like. Further, the folding roller pair 22 can be configured by continuously arranging a plurality of folding rollers (rotating bodies) in series along the axial direction of each of the folding rollers 22a and 22b.

As shown in FIG. 3, the folding roller 22a (first rotating body) has a first roller surface 22a2 (first circumferential surface) having a constant radius R1 around the rotation axis of the rotating shaft 22a1. and a second roller surface 22a3 (second peripheral surface) whose distance from the rotation axis of the rotation shaft 22a1 is smaller than the radius R1 of the first roller surface 22a2. The folding roller 22b (second rotating body) has a first roller surface 22b2 having a constant radius R1 around the rotation axis of the rotation shaft 22b1 and a distance from the rotation axis of the rotation shaft 22a1. is smaller than the radius R1 of the first roller surface 22b2. The first roller surfaces 22a2 and 22b2 are made of a rubber material or the like having a relatively high coefficient of friction, like a normal roller surface, and are pressed against each other to form a nip portion 22c. On the other hand, the second roller surfaces 22a3 and 22b3 are made of a plastic resin material or the like whose coefficient of friction is smaller than that of the first roller surfaces 22a2 and 22b2.

The rotating shafts 22a1 and 22b1 of the folding rollers 22a and 22b are rotationally driven by a folding roller motor 61 (FIG. 20) which is a common motor. Therefore, the folding rollers 22a and 22b rotate synchronously, and the rotational positions of the first roller surfaces 22a2 and 22b2 and the second roller surfaces 22a3 and 22b3 are always synchronized.

A folding blade 23 as a protruding member is arranged on the opposite side of the folding roller pair 22 with the sheet stacking tray 21 interposed therebetween. The folding blade 23 is carried by the blade carrier 24 with its tip facing the nip portion 22 c of the folding roller pair 22 . The blade carrier 24 is moved by a cam member 25, which will be described later, in a direction that crosses the sheet stacking tray 21 at a substantially right angle, that is, in a direction that intersects the transport direction of the sheet transported from the second discharge path 13b to the sheet stacking tray 21. It is set up so that it can run.

3, i.e., in the axial direction of the folding roller, on both sides of the blade carrier 24, cam members 25 each comprising a pair of mirror-symmetrical eccentric cams (only one of them is shown in the figure). are provided at opposing positions. The cam member 25 is rotated around a rotating shaft 25a provided at an eccentric position thereof by driving means such as a driving motor. A cam groove 25b is formed in the cam member 25 along its outer peripheral edge.

The blade carrier 24 is provided with a cam pin 24c as a cam follower, which is slidably fitted into the cam groove 25b.

The blade carrier 24 reciprocates toward or away from the sheet stacking tray 21 when the cam member 25 is rotated by the drive motor. As a result, as shown in FIG. 3, a position where the leading edge of the folding blade 23 does not enter the sheet conveying path formed by the sheet stacking tray 21 and a position where the leading edge of the folding blade 23 is pinched by the nip portion 22c of the folding roller pair 22 to a maximum protruding position. , the folding blade 23 can be linearly moved back and forth along the projecting path connecting the two positions. Here, the position where the tip of the folding blade 23 does not enter the sheet conveying path 20 formed by the sheet stacking tray 21 is the home position of the folding blade 23, and is initialized when the sheet processing apparatus B is turned on. The position returned by the control.

At the lower end of the sheet stacking tray 21, a regulating stopper 26 is arranged to abut and regulate the leading edge of the conveyed sheet in the conveying direction. The regulation stopper 26 is provided so as to be vertically movable along the sheet stacking tray 21 by a sheet lifting mechanism 27 .

The sheet lifting mechanism 27 of this embodiment is arranged below the blade carrier 24 when the folding blade 23 is at the home position on the back side of the sheet stacking tray 21, and is arranged along the sheet stacking tray 21 near its upper and lower ends. It is a conveyor belt mechanism comprising a pair of arranged pulleys 27a and 27b and a transmission belt 27c wound around the two pulleys. The regulation stopper 26 is fixed on the transmission belt 27c. By rotating the pulley 27a or 27b on the driving side by the regulation stopper motor 63 (FIG. 20), the regulation stopper 26 moves up and down between the lower end position shown in FIG. A sheet or sheet stack can be moved along the tray 21 .

The folding device F of this embodiment further includes a sheet side alignment mechanism for aligning and aligning the side edges of the sheets carried into the sheet stacking tray 21 . As shown in FIG. 4, the sheet side aligning mechanism has a pair of aligning plates 28a and 28b arranged symmetrically on both sides of the sheet stacking tray 21 in the sheet width direction (direction perpendicular to the sheet conveying direction). 4 is a schematic plan view of the folding device F viewed from above.

The aligning plates 28a and 28b are movably held so as to move toward or away from each other in the sheet width direction by rotating an aligning plate motor 65 (FIG. 20) forward or reverse. With respect to the sheet conveyed to the sheet stacking tray 21 and the leading edge of the sheet abutting against the regulation stopper 26, the aligning plates 28a and 28b are moved to abut on both ends of the sheet, thereby aligning the position of the sheet in the width direction.

Around the aligning plates 28a and 28b, an aligning plate sensor 66 such as an optical sensor detects when each of the aligning plates 28a and 28b is positioned at a home position outside the maximum sheet width in the sheet width direction. (FIG. 20) is provided. The aligning plates 28a and 28b are returned to their home positions by initialization control, which will be described later, when the power of the sheet processing apparatus B is turned on.

<Inner tri-fold processing>
The sheet processing apparatus B of the present embodiment can fold the sheet conveyed by the folding processing apparatus F onto the sheet stacking tray 21 serving as the sheet conveying path into three inwards. The in-three-folding process means that when a sheet is folded in two by the first folding process, and then the second folding process is performed on the sheet at a position different from the first folding position, the folding process is performed by the first folding process. In this process, one end of the folded sheet is folded into the inner side of the folded sheet by the second folding process to fold the sheet in three. A schematic operation of the inward three-folding process will be described below with reference to FIGS. 5 to 11. FIG. 5 to 11 are cross-sectional schematic diagrams showing the movement of each part along the flow of the sheet S when the inward three-folding process is executed.

The sheet stacking tray 21 of this embodiment is formed to be tilted with respect to the vertical direction, and the sheet S is guided by a guide surface 21a forming the sheet stacking tray 21 on one side thereof, and the sheet leading edge S1 is placed downward. The sheet is transported so that the trailing edge S2 faces up and falls, and the leading edge of the sheet hits the regulation stopper 26 and stops (FIG. 5A). At this time, the position of the regulation stopper 26 is arranged so that the first folding position of the sheet S against which the leading end S1 of the sheet abuts is the position facing the folding blade 23 . The folding blade 23 is arranged at a position to project the sheet S toward the folding roller pair 22 from the side of the guide surface 21 a of the sheet stacking tray 21 . In other words, the guide surface 21a of the sheet stacking tray 21 and the pair of folding rollers 22 are arranged at corresponding positions with the sheet S interposed therebetween.

In this state, after the position in the sheet width direction is aligned by the alignment plates 28 a and 28 b described above, the folding blade 23 is operated to fold the sheet S in two, and the folded portion is moved to the nip portion 22 c of the folding roller pair 22 . Stick out (Fig. 5(b)). In synchronism with the thrusting operation of the folding blade 23, the pair of folding rollers 22 and the discharge roller 17b are driven forward to convey the sheet S in the direction (first direction) in which it is drawn toward the pair of folding rollers 22 and the discharge roller 17b. As a result, the sheet S is pressed by the nip portion 22c of the folding roller pair 22 and subjected to the first folding process (FIG. 6A).

Next, in order to perform the second folding process, the sheet conveyance is stopped when the trailing edge S2 of the sheet that has undergone the first folding process reaches a predetermined position (FIG. 6B). Then, the discharge roller 17b is reversely driven to switch back and convey the sheet in a direction (second direction) opposite to the pulling direction. The trailing edge S2 of the sheet becomes an edge portion (hereinafter referred to as a "folding edge portion") that is folded inside the sheet that is folded in the second folding process when the sheet is folded in three. Then, when the switchback conveying process is performed, the L-shaped pressing guide member 30 presses the vicinity of the folded end S2 of the sheet downward (toward the sheet stacking tray 21 where the leading end S1 of the sheet is located) (FIG. 7A). ), and the pressing guide member 30 again guides the sheet S conveyed in the direction in which the regulation stopper 26 of the sheet stacking tray 21 is arranged (FIG. 7B). The configuration and operation of this pressing guide member 30 will be described later in detail.

When the leading edge of the sheet S reaches the regulation stopper 26 that has been moved to the sheet receiving position in advance by switchback conveyance (FIG. 8A), the pressing guide member 30 is moved from the guide surface 21a of the sheet stacking tray 21 to the sheet conveying path 20. 8(b)), and the regulating stopper 26 is moved to a position where the second folding position faces the folding blade 23 (FIG. 9(a)). After the movement is completed, the pressing guide member 30 is moved to the retracted position (FIG. 9(b)).

Next, the folding blade 23 is operated again to push the sheet S into the nip portion 22c of the folding roller pair 22 (FIG. 10(a)). At this time, a blade guide member 40, which is a protruding guide member arranged above the folding blade 23, protrudes so that the folded edge S2 of the sheet is guided to be pushed into the nip portion 22c (FIG. 10(b)). )). The configuration and operation of this blade guide member 40 will also be described in detail later.

The sheet S sent to the pair of folding rollers 22 by the protrusion of the folding blade 23 is subjected to a second folding process by passing through the nip portion 22c (FIG. 11(a)), and the sheet S folded in three is folded inward. It is discharged by the discharge roller 17b (FIG. 11(b)).

<Press guide member>
Next, the pressing guide member 30 (guide member) will be described with reference to FIGS. 12 to 14. FIG. 12 is a perspective view of the folding device F with the pressure guide member 30 exposed, and FIG. 13 is a diagram showing the relationship between the rotation trajectory of the pressure guide member 30 and other members. 14A and 14B are diagrams for explaining the operation of the pressing guide member 30. FIG.

<Shape of pressing guide member>
The pressing guide member 30 comes into contact with the vicinity of the folding end S2 (one end) of the sheet when the sheet that has undergone the first folding process is switchback-conveyed, thereby stacking the folding end S2 of the sheet. It guides the sheet to the side of the tray 21 where the other end of the sheet is positioned.

As shown in FIG. 12 (and see FIG. 4), the pressing guide member 30 sandwiches the sheet S guided by the guide surface 21a of the sheet stacking tray 21 and is located on the side opposite to the side on which the folding roller pair 22 is arranged. are placed in In the present embodiment, three of them are attached to the rotating shaft 31, which is a support member arranged in the seat width direction, side by side at substantially equal intervals. The two on both sides are arranged at positions where they can come into contact with both ends of the sheet S conveyed on the sheet stacking tray 21, and the central one is arranged at a position where they can come into contact with the conveyed sheet at substantially the center in the width direction. It is

The pressing guide member 30 is configured to be rotatable by the driving force of a pressing guide motor 33 . Specifically, the rotary shaft 31 is connected to a pressing guide motor 33 via a drive transmission member 32 such as a drive belt, and the driving force of the pressing guide motor 33 causes the rotary shaft 31 to rotate. The three pressing guide members 30 rotate integrally.

As shown in FIG. 13, the pressing guide member 30 includes a rotating portion 30a that can rotate about a rotating shaft 31, and a guide portion serving as a first guide surface that abuts and guides the sheet S conveyed in a switchback manner. 30b, and the guide portion 30b is connected substantially perpendicularly to the rotating portion 30a. A pressing portion 30c that presses the sheet S is formed between the rotating portion 30a and the guide portion 30b, that is, the L-shaped corner portion that is the tip of the rotating portion 30a.

The pressing guide member 30 is provided so as to form a notch in the guide surface 21a and be exposed therefrom. When the sheet S is carried into the sheet stacking tray 21, it is retracted to the retracted position (see FIG. 5A). At this retracted position (first position), the rotating portion 30a is positioned so that the sheet stacking tray 21 is moved toward the sheet stacking tray 21 through the sheet transporting path 20 after being transported from the image forming apparatus A so as not to interfere with the movement of the sheet. It is set at a position substantially flush with the guide surface 21a or at a position retreated from the sheet conveying path 20 relative to the guide surface 21a. By setting the retracted position to a position where the rotating portion 30a is substantially flush with the guide surface 21a of the sheet stacking tray 21, the rotating portion 30a functions as a part of the guide surface 21a and the sheet is carried into the sheet stacking tray 21. Since the guide surface can act as a guide surface for guiding the sheet to be pushed, it is possible to prevent the sheet from being caught in the notch formed in the guide surface 21a. The position where the guide surface 21a and the guide surface 21a are substantially flush with each other is a configuration in which the rotating portion 30a and the guide surface 21a are completely flush with each other, and a tolerance range between the rotating portion 30a and the guide surface 21a. It also includes configurations that are out of alignment.

<Position of rotation center>
As shown in FIG. 13, the rotation shaft 31 serving as the center of rotation of the pressing guide member 30 of the present embodiment is positioned closer to the sheet S than the nip line L1 connecting the nip portion 22c of the folding roller pair 22 and the folding blade 23. is arranged on the upstream side in the conveying direction of the sheet stacking tray 21, and is arranged on the opposite side of the guide surface 21a of the sheet stacking tray 21 to the side on which the folding roller pair 22 is arranged. Further, the rotating shaft 31 of this embodiment passes through the rotating shaft 22a1 of the folding roller 22a, which is closer to the rotating shaft 31 of the folding rollers 22a and 22b, than the rotating shaft line L2 parallel to the nip line L1. are also arranged on the downstream side in the conveying direction.

The rotating portion 30a is set so as to rotate in a direction in which the pressing portion 30c presses the sheet S to the switchback conveying side.

Therefore, when the sheet S that has undergone the first folding process is switchback-conveyed, as shown in FIG. , the pressing portion 30c presses down the folded end portion S2 of the sheet from above the folded end portion S2. As a result, the folded end portion S2 is guided downstream (downward) in the sheet conveying direction in which the sheet S is received by the sheet stacking tray 21 before the sheet stacking tray 21 is subjected to the first folding process while being switchback-conveyed. be.

Further, as shown in FIG. 14(c), when the pressing portion 30c rotates to the position of the guide surface 21a, the pressing portion 30c abuts against the sheet and then pushes the folded edge S2 of the sheet from the nip portion 22c side to the guide surface 21a. The sheet stacking tray 21 is pushed down so as to be drawn in to the side, and is guided so as to be guided in the direction in which the regulation stopper 26 of the sheet stacking tray 21 is arranged. Therefore, even if the folded edge S2 of the sheet is curled upward, the sheet is reliably conveyed downward without advancing upward on the sheet stacking tray 21 .

<Rotating Area of Rotating Part>
As shown in FIG. 13, the length of the rotating portion 30a of the pressing guide member 30 of the present embodiment, that is, the length from the rotating shaft 31, which is the fulcrum of rotation, to the pressing portion 30c is equal to the length of the two folding rollers 22a. , 22b, it is longer than the shortest distance to the first roller surface 22a2 of the folding roller 22a on the side closer to the rotation shaft 31 and shorter than the shortest distance to the second roller surface 22a3.

As described above, when the length of the rotating portion 30a is set to be longer than the shortest distance to the first roller surface 22a2, and the pressing guide member 30 is rotated from the retracted position toward the sheet conveying path 20, the folded sheet is folded. By positioning the second roller surfaces 22a3 and 22b3 of the roller pair 22 at a position facing the rotating portion 30a, the pressing guide member 30 can be rotated without causing the rotating portion 30a to interfere with the folding roller pair 22. can. Since the rotating portion 30a is longer than the shortest distance to the first roller surface 22a2 of the folding roller 22a, compared to a structure in which the rotating portion 30a is shorter than the shortest distance to the first roller surface 22a2, switchback conveyance is possible. The pressing portion 30c can be brought into contact with the sheet to be pressed at a position closer to the nip portion 22c. Therefore, the sheets can be stably guided to the sheet stacking tray 21 .

Here, the pressing portion 30c of the pressing guide member 30 abuts on the sheet that is being switched back by the folding roller pair 22, and guides the folded end S2 of the sheet to the side of the sheet stacking tray 21 where the other end of the sheet is positioned. Let the position where it carries out is a guide position (2nd position). This guide position is set outside the region between the locus of rotation of the first roller surface 22a2 and the locus of rotation of the second roller surface 22a3. With such a configuration, when the pressing guide member 30 abuts on the sheet and guides the sheet, the pressing guide member 30 interferes with the first roller surface 22a2 of the folding roller 22a that rotates to switch back the sheet. can be prevented. That is, when the pressing guide member 30 rotates from the retracted position to the guide position, it enters the area between the rotation locus of the first roller surface 22a2 and the rotation locus of the second roller surface 22a3, and exits the area. It abuts on the sheet at the guide position located. Note that the retracted position of the pressing guide member 30 is also located outside the area between the rotation trajectory of the first roller surface 22a2 and the rotation trajectory of the second roller surface 22a3.

In the present embodiment, the pressing portion 30c of the pressing guide member 30 contacts the sheet that is switched back by the folding roller pair 22 at the guide position, and presses the sheet downward, thereby guiding the sheet. is. However, at least when the pressing guide member 30 moves from the retracted position to the guide position, it enters the area defined by the movement locus of the folding roller 22a, and contacts the sheet at the guide position outside the area. is guided to the above-described position, the effect of stably guiding the sheet to the sheet stacking tray 21 can be obtained.

When the rotating portion 30a is lengthened, the rotating shaft 31 must be positioned away from the folding blade 23 in the sheet conveying direction in order to prevent the rotating pressing guide member 30 from interfering with the folding blade 23. will not be. As a result, the rotating shaft 31 must be arranged at a position away from the folding roller pair 22 as well. In this regard, in the present embodiment, as described above, the rotating shaft 31 is arranged between the nip line L1 and the rotation axis L2 in the sheet conveying direction. The position at which the pressing portion 30c presses the sheet that is conveyed in the switchback can be brought closer to the nip portion 22c without increasing the length of .

Further, as shown in FIG. 13, the pressing guide member 30 of the present embodiment has a shape in which the guide portion 30b is located inside the rotation locus L3 of the rotation portion 30a and does not protrude outside the region. As a result, the guide portion 30b does not interfere with the folding roller pair 22 even when the long rotating portion 30a is rotated as described above.

When the sheet that has undergone the first folding process as described above is conveyed by switchback, the sheet is guided by the pressing guide member 30 and returned to the sheet stacking tray 21 . After the sheet comes into contact with the regulation stopper 26 and the switchback conveyance is completed, the pressing guide member 30 is moved to a position slightly projecting toward the sheet conveying path 20 from the guide surface 21a (see FIG. 8B). .

After that, the regulation stopper 26 is lifted and the sheet is reversely conveyed so that the second folding position faces the folding blade 23 . At this time, since the pressing guide member 30 is located at a position slightly projecting toward the sheet conveying path 20 from the guide surface 21a, the sheet S is guided by the rotating portion 30a of the pressing guide member 30 and formed on the guide surface 21a. It is conveyed without being caught in the cutout for attaching the pressing guide member (see FIG. 9(a)). After the second folding position of the sheet moves to the position facing the folding blade 23, the pressing guide member 30 is returned to the retracted position.

<Position Control of Folding Roller Pair and Pressing Guide Member>
Next, position control of the folding roller pair 22 and the pressing guide member 30 will be described.

FIG. 23 is a perspective view of the periphery of the pressing guide member 30 in the folding device F viewed from the back side of the guide surface 21a of the sheet stacking tray 21 (opposite side to the sheet conveying path 20). 24 is a schematic cross-sectional view of the folding roller pair 22 and the pressing guide member 30. FIG. 23(a) and 24(a) show a state where the pressing guide member 30 is located at the retracted position. 23(b) and 24(b) show a state where the pressing guide member 30 is positioned at the guide position.

As shown in FIGS. 23 and 24, the folding device F has a pressure guide position detection unit 90 for detecting that the pressure guide member 30 is positioned at the retracted position or the guide position. The pressure guide position detection unit 90 is composed of two flags 90a and 90b rotating in synchronization with the pressure guide member 30, and two optical sensors 90c and 90d arranged around the flags 90a and 90b.

The flag 90a is attached to the pressing guide member 30 positioned at the central portion in the sheet width direction among the three pressing guide members 30 . The optical sensor 90c is arranged at a position that detects the flag 90a when the pressing guide member 30 is positioned at the retracted position. When the optical sensor 90c detects the flag 90a, it outputs a detection signal to the control section 60 (FIG. 20). That is, the flag 90a and the optical sensor 90c are a detection section (first detection section) that detects that the pressing guide member 30 is positioned at the retracted position. This retracted position is the home position of the pressing guide member 30, and the pressing guide member 30 is returned to the retracted position by initialization control, which will be described later, when the power of the sheet processing apparatus B is turned on. In this embodiment, a transmissive phototransistor is used as the photosensor 90c, but other transmissive photosensors or reflective photosensors may be used.

The flag 90b is supported by the rotary shaft 31 at a position outside the sheet conveying area in the sheet width direction. The optical sensor 90d is arranged at a position for detecting the flag 90b when the pressing guide member 30 is positioned at the guide position. The optical sensor 90d outputs a detection signal to the control unit 60 when the flag 90b is detected. That is, the flag 90b and the optical sensor 90d are a detection section (third detection section) that detects that the pressing guide member 30 is positioned at the guide position. In this embodiment, a transmissive phototransistor is used as the photosensor 90d, but other transmissive photosensors or reflective photosensors may be used.

When the pressure guide member 30 is moved from the guide position to the retracted position, the controller 60 rotates the pressure guide motor 33 forward (rotates in the first rotation direction). As a result, the pressing guide member 30 rotates from the guide position toward the retracted position. Then, when the control unit 60 receives the detection signal of the flag 90a from the optical sensor 90c, it stops driving the pressing guide motor 33. FIG. Here, even after the driving of the pressing guide motor 33 is stopped, the rotating shaft 31 rotates due to the inertial force, and the pressing guide member 30 and the flags 90a and 90b also rotate accordingly. The flag 90b rotated by inertial force abuts on a regulating portion 98 provided on the back side of the guide surface 21a of the sheet stacking tray 21. As shown in FIG. As a result, the rotation of the rotary shaft 31 is restricted, and the pressing guide member 30 is positioned at the retracted position. Note that the restricting portion 98 is made of an elastic material such as rubber in order to suppress impact and vibration when the flag 90b abuts. In this manner, the pressing guide member 30 is moved from the guide position to the retracted position.

When the pressure guide member 30 is moved from the retracted position to the guide position, the controller 60 reverses the pressure guide motor 33 (rotates in the second rotation direction). As a result, the pressing guide member 30 rotates from the retracted position toward the guide position. Then, when the control unit 60 receives the detection signal of the flag 90b from the optical sensor 90d, it stops driving the pressing guide motor 33. FIG. Here, even after the pressing guide motor 33 stops being driven, the rotating shaft 31 rotates due to the inertial force, and the pressing guide member 30 also rotates accordingly. The pressing guide member 30 that rotates due to inertia comes into contact with the regulating portion 99 provided on the sheet stacking tray 21 . As a result, the rotation of the rotary shaft 31 is restricted, and the pressing guide member 30 is positioned at the guide position. Note that the restricting portion 99 is made of an elastic material such as rubber in order to suppress impact and vibration when the pressing guide member 30 comes into contact with it. In this manner, the pressing guide member 30 is moved from the retracted position to the guide position.

The folding device F also has a folding roller position detection unit 91 (second detection section) that detects when the folding roller pair 22 is positioned at a home position, which will be described later. The folding roller position detection unit 91 is supported by the rotating shaft 22a1 of the folding roller 22a and is composed of a flag holding roller 91a having a flag 91a1 and an optical sensor 91b arranged around the flag holding roller 91a.

Since the flag holding roller 91a is supported by the rotating shaft 22a1 of the folding roller 22a, it rotates in synchronization with the folding roller 22a. The optical sensor 91b is arranged at a position where the flag 91a1 is detected when the second roller surface 22a3 of the folding roller 22a and the second roller surface 22b3 of the folding roller 22b are located at the home position where they are separated from each other while facing each other. (Fig. 24(a)). This home position is also a position where the folding roller pair 22 does not interfere with the rotation of the pressing guide member 30 . The optical sensor 91b outputs a detection signal to the control unit 60 when the flag 91a1 is detected. In this embodiment, a transmissive phototransistor is used as the photosensor 91b, but other transmissive photosensors or reflective photosensors may be used. The flag 91a1 is not limited to the configuration of the present embodiment as long as it rotates in synchronization with the rotation of the folding roller 22a. A configuration in which 91a1 is provided, or a configuration in which a flag holding roller 91a is provided on the rotating shaft of the gear may be used.

<Blade guide member>
After the second folding position of the sheet that has been switchback-conveyed as described above moves to a position facing the folding blade 23, the pressing guide member 30 is moved to the retracted position, and the folding blade 23 is operated to perform the second fold. fold operation. At this time, the blade guide member 40 provided above the folding blade 23 guides the folded edge S2 of the sheet (see FIG. 10B).

Next, the configuration and operation of the blade guide member 40 will be specifically described with reference to FIGS. 15 to 19. FIG. 15A and 15B are diagrams for explaining the rotation of the blade guide member 40, and FIGS. 16 to 19 are diagrams showing the operations of the folding blade 23 and the blade guide member 40 when the sheet is folded for the second time. is.

<Configuration of blade guide member>
The blade guide member 40 moves in the projecting direction of the folding blade 23 when performing the second folding process on the sheet S, and moves the folding blade 23 along the fold side of the sheet formed by the first folding process. The end portion, ie, the sheet folding end portion S2 is guided in the projecting direction to the nip portion 22c of the folding roller pair 22. As shown in FIG. Therefore, as shown in FIG. 15, the blade guide member 40 has a contact portion 40a that contacts the rear end of the sheet, and a fitting hole portion 40b that has a partial notch at one end of the contact portion. is formed, and this fitting hole portion 40b is rotatably fitted to the shaft portion 40f formed in the base portion 40e. An arm portion 40c is integrally provided at the other end of the contact portion 40a, and an engaging projection 40d is formed at the end of the arm portion 40c. The engaging protrusion 40d is slidably engaged with an elongated hole 50 formed in the frame of the sheet processing apparatus B. As shown in FIG. The elongated hole 50 is formed substantially parallel to the guide surface 21 a of the sheet stacking tray 21 in the vicinity of the upper portion of the blade carrier 24 .

The base portion 40e is attached to the blade carrier 24 so as to be slidable in a direction parallel to the moving direction of the blade carrier 24. As shown in FIG. A tension spring 51 is attached between a locking portion 40e1 formed on the base portion 40e and a locking portion 24a formed on the blade carrier 24. As shown in FIG.

The blade carrier 24 is provided with a pressing protrusion 24b capable of contacting and pressing against the base portion 40e. The pressing protrusion 24b is rotatably provided on the blade carrier 24 and is urged counterclockwise in FIG. 15 by a coil spring 52 attached to a rotating shaft. As a result, when the blade carrier 24 moves in the blade projecting direction, the pressing projection 24b abuts against the base portion 40e to press the base portion 40e, and the blade guide member 40 moves integrally with the blade carrier 24. As shown in FIG. The coil spring 52 provided on the pressing protrusion 24b acts as a so-called torque limiter, and rotates clockwise when a predetermined clockwise force is applied to the pressing protrusion 24b. there is

<Change in Angle of Contact Portion with respect to Moving Direction of Folding Blade>
15(a), when the blade carrier 24 is at the home position, the contact portion 40a of the blade guide member 40 is pulled by the tension spring 51 so that the pressing guide member 30 rotates. It is in a position in contact with the rotating shaft 31 that serves as a fulcrum. This state is the home position of the blade guide member 40 . At this time, the abutting portion 40a stands up so as to be substantially flush with the guide surface 21a. When the blade carrier 24 moves in the blade projecting direction from the home position, the blade guide member 40 is pressed by the pressing protrusion 24b and moves together with the blade carrier 24, and as shown in FIG. The abutting portion 40 e 2 erected at the rear end of the portion 40 e is moved until it abuts against the rotating shaft 31 .

As described above, when the blade guide member 40 moves in the blade projecting direction, the engaging protrusion 40d is guided by the long hole 50 and slides downward, and the contact portion 40a rotates about the shaft portion 40f. Therefore, in the state shown in FIG. 15A where the blade guide member 40 is at the home position, the contact portion 40a is substantially perpendicular to the moving direction of the blade carrier 24, that is, the moving direction of the folding blade 23, and is in an upright state. . As the blade carrier 24 moves in the direction in which the folding blade 23 protrudes, as shown in FIG. The angle of the contact portion 40a with respect to the direction of movement is configured to change sharply as it moves.

Further, as shown in FIG. 15A, a protrusion 40f1 is formed on the shaft portion 40f that serves as the rotation shaft of the contact portion 40a. On the other hand, the notch formed in the fitting hole portion 40b to be fitted with the shaft portion 40f is formed wider than the width of the protrusion 40f1, and the blade guide member 40 is rotatable within the range of the notch. .

In the above configuration, when the blade carrier 24 moves to the home position, the base portion 40e is pulled by the tension spring 51. At this time, the cutout surface of the fitting hole portion 40b abuts on the protrusion 40f1 and the abutment portion 40a. further rotation is restricted. Therefore, further movement of the blade guide member 40 is restricted while the contact portion 40a is in contact with the rotating shaft 31, and the contact portion 40a maintains the upright state at the home position.

Further, in the blade guide member 40 of the present embodiment, the contact portion 40a and the arm portion 40c are composed of linear members when viewed in cross section, and the arm portion 40c has a predetermined angle with respect to the contact portion 40a. formed. As a result, even when the blade guide member 40 is at the home position, the engaging protrusion 40d of the arm portion 40c is provided even when the contact portion 40a is substantially flush with the guide surface 21a. The side end is located farther from the guide surface 21a on the side opposite to the side on which the folding roller pair 22 is located. Therefore, the elongated hole 50 with which the engaging protrusion 40d engages can be arranged away from the guide surface 21a on the side opposite to the folding roller pair 22, and arranged at a position where it does not interfere with the guide surface 21a. can. Therefore, when the blade guide member 40 is at the home position, the contact portion 40a can be configured to function as a guide portion for the sheet conveyed on the sheet stacking tray 21. FIG.

<Operation of Folding Blade and Blade Guide Member>
Next, the operation of the blade guide member 40 when the folding blade 23 is operated to fold the sheet for the second time will be described with reference to FIGS. 16 to 19. FIG.

FIG. 16(a) shows the state where the blade carrier 24 is at the home position, and at this time the blade guide member 40 is also at the home position. In the following description, the direction in which the blade carrier 24 projects the folding blade 23 from the position of the home position to the nip portion 22c of the folding roller pair 22 is the "extrusion direction", and the direction in which the folding blade 23 is returned from the nip portion 22c side to the home position. It is called "return direction".

When the folding blade 23 is at the home position, the folding blade 23 is also at the home position. away from S. Therefore, the sheet conveyed on the sheet stacking tray 21 while being guided by the guide surface 21a will not be caught by the leading edge of the blade. Even when the tip of the folding blade 23 protrudes toward the folding roller 22 from the guide surface 21a, the tip of the blade does not convey the sheet unless a sheet conveyed to the sheet stacking tray 21 by another guide member is caught by the tip of the blade. Since it can be said that the vehicle has evacuated from the road, that position may be used as the home position. When the blade guide member 40 is at the home position, the contact portion 40a of the blade guide member 40 is in contact with the rotating shaft 31. As shown in FIG. At this time, the pressing protrusion 24b is separated from the base portion 40e.

Next, in order to project the folding blade 23, when the cam drive motor is driven, the cam member 25 rotates to move the blade carrier 24 in the projecting direction. Then, the pressing protrusion 24b comes into contact with the base portion 40e, and the blade guide member 40 moves integrally with the blade carrier 24 and the folding blade 23 in the projecting direction (FIG. 16(b)). At this time, the tip of the folding blade 23 is configured to protrude further in the protrusion direction than the tip of the blade guide member 40 .

When the blade carrier 24 moves further in the projecting direction, the tip of the folding blade protrudes by a predetermined amount, and as shown in FIG. , the tip of the folding blade 23 contacts the sheet S stopped on the sheet stacking tray 21 . At this time, since the tip of the folding blade 23 protrudes further than the blade guide member 40 as described above, the folding blade 23 comes into contact with the folding position of the sheet S before the blade guide member 40 does. For this reason, due to the protrusion of the folding blade 23, the leading edge of the folding blade facing the folding position of the sheet is accurately brought into contact with the folding position without deviation from the folding position of the sheet, and the folding process is executed at the accurate folding position.

Even if the tip of the folding blade does not necessarily protrude from the blade guide member 40, if the tip of the folding blade is positioned at the same position as the blade guide member 40 in the direction of protrusion, the tip of the folding blade can be prevented from being misaligned with the folding position of the sheet. can be suppressed.

When the blade carrier 24 moves in the projecting direction in the above state, the folding blade 23 projects the second folding position of the sheet S toward the nip portion 22 c of the folding roller pair 22 . At the same time, the contact portion 40a of the blade guide member 40 contacts the folded edge S2 of the first folded sheet and guides the folded edge S2 to the nip portion 22c (see FIG. 3). 17(b)).

As described above, since the blade guide member 40 guides the folded edge S2 of the sheet to the nip portion 22c, the folded edge S2 of the sheet moves toward the nip portion 22c without being turned over. Also, when approaching the nip portion 22c, the protruding blade guide member 40 may interfere with the outer peripheral surfaces of the folding rollers 22a and 22b. At this time, as the blade guide member 40 of this embodiment moves in the projecting direction as described above, the angle of the contact portion 40a with respect to the projecting direction changes to an acute angle (from the state in FIG. 17(a) to the state in FIG. 17( change to the state of b)). Therefore, the contact portion 40a can enter closer to the nip portion 22c, and the folded end portion S2 of the sheet can be reliably guided to the nip portion.

When the blade carrier 24 moves further in the projecting direction and the abutting portion 40e2 comes into contact with the rotating shaft 31 as shown in FIG. 17(b), the blade guide member 40 is restricted from moving further in the projecting direction. . Note that when the blade guide member 40 moves most in the projecting direction, the tip of the blade guide member 40 (the end on the side of the pair of folding rollers 22 with respect to the projecting direction) is positioned at the sheet loading tray of the folding rollers 22a and 22b. It protrudes toward the nip portion 22c from the tangent line (of the two folding rollers 22a and 22b) connecting the outer peripheries on the 21 side. On the other hand, when the blade carrier 24 is pushed out in the projecting direction by the rotation of the cam member 25, as shown in FIG. It rotates clockwise against the urging force and slips under the base portion 40e. As a result, the pressing projection 24b no longer presses the blade guide member 40, and while the blade guide member 40 remains stationary, only the folding blade 23 moves in the projecting direction, and the tip of the blade protrudes to the maximum to push the sheet S into the nip portion 22c. Move to a position where it sticks out. At this time, the tip of the folding blade 23 projects farther than the tip of the contact portion 40 a of the blade guide member 40 . That is, the distance from the tip of the blade to the tip of the contact portion at the protruded position is the distance from the tip of the blade to the tip of the contact portion when the tip of the folding blade 23 contacts the sheet S stopped on the sheet stacking tray 21 . greater than the distance to As a result, the sheet is reliably pulled into the nip portion 22c of the folding roller pair 22 while being folded at the second folding position, and the leading edge S1 of the sheet is also pulled into the nip portion 22c to be folded in three. Become.

When the folding blade 23 is projecting the sheet, that is, while the tip of the folding blade 23 is moving from the position where the tip of the folding blade 23 contacts the sheet S stopped on the sheet stacking tray 21 to the projecting position, the blade When a large load is applied to the guide member 40 in the return direction, for example, when a plurality of sheets are folded in a state of being stacked and the rigidity of the sheet is high, a large load is applied to the blade guide member 40 during the folding process. It takes. In this case, when a load exceeding a certain level is applied, the blade guide member 40 moves against the folding blade 23 against the frictional force of the pressing protrusion 24b which is pressed against the bottom surface of the base portion 40e by the biasing force of the coil spring 52. It is relatively movable in the return direction. As a result, the blade guide member 40 is not damaged when a large load is applied to the blade guide member 40 during the sheet folding process.

When the cam member 25 further rotates after the tip of the folding blade reaches the protruding position, the blade carrier 24 moves in the return direction together with the folding blade 23 (FIG. 18(b)). At this time, as described above, the pressing projection 24b is in pressure contact with the base portion 40e of the blade guide member 40 by the biasing force of the coil spring 52, so that the friction between the pressing projection 24b and the bottom surface of the base portion 40e causes the blade to move. The guide member 40 also moves integrally with the blade carrier 24, i.e. simultaneously with the folding blade 23, in the returning direction.

When the cam member 25 further rotates and the blade carrier 24 moves in the return direction, the contact portion 40a of the blade guide member 40 contacts the rotating shaft 31, and the blade guide member 40 returns to the home position. Further movement of the blade guide member 40 in the return direction is restricted (FIG. 19(a)). When the cam member 25 rotates further, only the folding blade 23 moves in the return direction and returns to the home position while the blade guide member 40 does not move (FIG. 19(b)).

As described above, when the blade carrier 24 moves in the return direction, the folding blade 23 and the blade guide member 40 simultaneously move in the return direction, and the blade guide member 40 causes the blade carrier 24 and the folding blade 23 to return to their home positions. Return to home position before. That is, the blade guide member 40 retreats earlier than the folding blade 23 from the sheet pulled in by the folding roller pair 22 and the discharge roller 17b. Therefore, the conveying load of the blade guide member 40 on the sheet S drawn by the discharge roller 17b or the like is reduced.

<Arrangement relationship between blade guide member and pressing guide member>
In this embodiment, as shown in FIG. 4, which is a schematic plan view of the folding device F, two blade guide members 40 are arranged at predetermined positions in the sheet width direction. The folding blade 23 of the present embodiment has four projecting tip portions 23a at approximately equal intervals in the sheet width direction on the projecting side. When the pushing end portion 23a pushes the sheet, the sheet is pushed out to the nip portion 22c of the folding roller pair 22, and the folding process is executed. The blade guide member 40 is arranged above the two tip end portions 23a of the four tip end portions 23a. Therefore, the sheet S pushed out by the folding blade 23 is guided by the blade guide members 40 at the folded ends S2 on both sides in the width direction.

The blade guide member 40 is desirably arranged above all four piercing tip portions 23a in order to guide the folded end portion S2 of the sheet to the nip portion 22c. increases. On the other hand, in the present embodiment, as described above, the blade guide members 40 are arranged at the positions of the two thrust tip portions 23a formed at both ends in the sheet width direction, so that the number of parts can be reduced. . Since the folded end portion S2 of the sheet pushed out by the folding blade 23 in the second folding process is more likely to be turned over in the vicinity of the end portion than in the center portion in the sheet width direction, this portion is nipped by the blade guide member 40. By guiding in the direction, the turning-up can be effectively prevented.

The two blade guide members 40 are arranged not at both ends in the width direction of the sheet, but above the tip end portion 23a formed slightly closer to the center. This is because it is more effective to poke the sheet slightly closer to the center than to the ends in the width direction when the sheet is pushed out by the thrusting tip 23a, and the blade guide member 40 corresponds to the position of the thrusting tip 23a. This is because they are arranged.

With respect to the position of the blade guide member 40, the pressing guide member 30 of the present embodiment is arranged outside the two blade guide members 40 in the sheet width direction. Specifically, the two pressing guide members 30 are arranged at intervals substantially equal to the width of the minimum size sheet that can be processed by the folding device F, and when folding the minimum size sheet, the width of the sheet is reduced. It is placed at a position where both ends can be pressed and guided. In this embodiment, in addition to the two pressing guide members 30 capable of pressing and guiding both ends of the sheet, a pressing guide member 30 capable of pressing and guiding the center in the width direction of the sheet is provided. Three pressing guide members 30 are provided. More specifically, the minimum size sheet that can be processed by the folding device F in this embodiment is A4, and the width of a general A4 size sheet in the lateral direction is 210 mm. Two pressing guide members 30 capable of pressing and guiding both ends in the width direction of the sheet are formed to have a length of 18 mm in the width direction of the sheet. The length of the straight line is 226 mm, which is longer than the width of the A4 size sheet, and the ends of the A4 size sheet in the width direction extend 10 mm on each side of the pressing guide member 30 near the center in the width direction. . The maximum size sheet that can be processed by the folding device F is A3, and the width of a general A3 size sheet in the width direction is 297 mm. By setting the length obtained by connecting the outer ends of two pressing guide members 30 that can press and guide both ends of the sheet in the width direction with a straight line longer than the width of the minimum size sheet, the maximum size sheet can be obtained. It is possible to give the guide effect also to the end of the .

When feedback-conveying a sheet that has undergone the first folding process, the pressing guide member 30 presses the folding end S2 of the sheet and guides it back to the sheet stacking tray 21 as described above. It is effective to prevent turning-up by pressing and guiding both ends in the direction. Therefore, the two pressing guide members 30 are arranged outside the blade guide member 40 in the sheet width direction. In the present embodiment, the pressure guide members 30 arranged on both sides in the sheet width direction are arranged at intervals substantially equal to the width of the minimum size sheet, and the blade guide members 40 are positioned inside the width of the minimum size sheet. are also spaced at short intervals.

<System Configuration of Folding Device>
Next, the system configuration of the folding device F will be described.

FIG. 20 is a block diagram showing the system configuration of the folding device F. As shown in FIG. As shown in FIG. 20, the folding device F has a control section 60 comprising a CPU (not shown), a memory (not shown), and a timer (not shown).

The control unit 60 includes a folding roller motor 61 (second motor) that rotates the folding roller pair 22, a discharge roller motor 62 that rotates the discharge roller 17b, and a regulation stopper motor that operates the sheet lifting mechanism 27 that raises and lowers the regulation stopper 26. 63 are connected. Also connected to the control unit 60 are a cam motor 64 that drives the cam member 25, a pressing guide motor 33 (first motor) that rotates the pressing guide member 30, and an alignment plate motor 65 that moves the alignment plates 28a and 28b. .

Also connected to the control unit 60 are an optical sensor 90c for detecting that the pressing guide member 30 is at the retracted position, and an optical sensor 90d for detecting that it is at the guiding position. Also connected to the control unit 60 are an optical sensor 91b for detecting that the folding roller pair 22 is at the home position, and an alignment plate sensor 66 for detecting that the alignment plates 28a and 28b are at the home position. .

<Sheet folding control>
Next, the control of the control unit 60 when performing sheet folding processing will be described. 21 and 22, the control unit 60 operates a folding roller motor 61 that drives and rotates the folding roller pair 22, a discharge roller motor 62 that drives and rotates the discharge roller 17b, and moves the regulation stopper 26 up and down. control the driving of the regulation stopper motor 63 that operates the sheet lifting mechanism 27; Similarly, the control unit 60 drives and controls the cam motor 64 that drives the cam member 25 for operating the blade carrier 24 and the pressing guide motor 33 that rotates the pressing guide member 30 .

FIGS. 21 and 22 show a state in which the sheet S is conveyed to the sheet stacking tray 21, the leading edge of the sheet abuts the regulation stopper 26 stopped at a predetermined position, and the first folding position is opposed to the folding blade 23. 4 is a flowchart showing a drive control procedure when executing folding processing;

When the folding process is executed, the cam motor 64 is driven to move the blade carrier 24 in the projecting direction, and the folding blade 23 contacts the first folding position of the sheet S and projects to the nip portion 22c (S1). At the same time, the folding roller motor 61 and the discharge roller motor 62 are driven to rotate the folding roller pair 22 and the discharge roller 17b forward (S2). Each motor is a pulse motor, and when the motor is driven, the number of driving pulses is counted.

When the cam member 25 rotates, the folding blade 23 protrudes the first folding portion of the sheet S to the nip portion 22c of the folding roller pair 22 by a predetermined amount. and return (S3).

The sheet S projected into the nip portion 22c of the folding roller pair 22 by the protrusion of the folding blade 23 is folded while being nipped and transported by the folding roller pair 22, and together with the folding roller pair 22, constitutes the sheet transporting means. It is conveyed by the discharging roller 17b. When the sheet is nipped and conveyed by the discharge roller 17b (S4), the folding roller motor 61 stops when the second roller surfaces 22a3 and 22b3 of the folding rollers 22a and 22b face each other (S4 and S5). As a result, the folding roller pair 22 no longer nips the sheet, and the sheet is conveyed by the discharge roller 17b. At this time, the sheet is conveyed by the discharge roller 17b while being guided by the second roller surfaces 22a3 and 22b3 having a small coefficient of friction. In the present embodiment, whether the sheet is conveyed to the discharge roller 17b or whether the second roller surfaces 22a3 and 22b3 of the pair of folding rollers face each other is determined by the pulse count of the motor. S may be detected by a sensor, and the drive of the motor may be controlled according to the detection result.

Then, when the position of the folded edge S2 of the conveyed sheet S reaches the predetermined area (S7), the drive of the discharge roller motor 62 is stopped to stop the sheet conveying (S8). This predetermined area is an area between the folded end portion S2 of the sheet S and the guide surface 21a of the sheet stacking tray 21 and the rotation locus L3 of the pressing guide member 30 (see FIG. 14A). By stopping the sheet S so that the folding end portion S2 is within the region, when the pressing guide member 30 is rotated, the pressing portion 30c can reliably press the sheet S in the switchback conveying direction. (See FIG. 14(b)), and furthermore, the folded end S2 that is conveyed switchback can be guided by the guide portion 30b (see FIG. 14(c)).

After the folding end S2 of the sheet S is stopped in the region, the pressing guide motor 33 is driven to move the pressing guide member 30 through the guide position to the position shown in FIG. 14(c). 30 is rotated (S9). Further, along with the rotation of the pressing guide member 30, the regulation stopper motor 63 is driven to move the regulation stopper 26 to a position where it can receive the sheet S to be switchback-conveyed.

Next, after the pressing guide member 30 is rotated as described above, the control section 60 reversely drives the discharge roller motor 62 and the folding roller motor 61 (S10). As a result, the discharge roller 17b and the pair of folding rollers 22 rotate in the reverse direction, and the sheet S is conveyed in a switchback manner. At this time, since the sheet is guided by the pressing guide member 30 as described above, the sheet is switchback-conveyed in the direction in which the regulation stopper 26 of the sheet stacking tray 21 is arranged without any conveyance failure.

When moving the pressure guide member 30 from the retracted position to the guide position, the control unit 60 does not receive the detection signal of the flag 90b from the optical sensor 90d within a predetermined time after the pressure guide motor 33 is reversed. In this case, there is a possibility that the pressing guide member 30 is caught on the sheet and cannot be rotated. If the folding roller motor 61 is driven in this situation, the pressing guide member 30 and the folding roller pair 22 may interfere with each other and be damaged. Therefore, in such a case, the control unit 60 stops driving the folding roller motor 61 and the pressing guide motor 33 and notifies an error. The error notification method is the same as the method described in the initialization control, which will be described later. Such a situation occurs when the basis weight of the sheets to be folded is large (the number of thick sheets or sheet bundles is large) and the stiffness of the sheets is equal to or greater than the turning force of the pressing guide member 30. obtain.

The discharge roller motor 62 and the folding roller motor 61 are driven to switchback convey the sheet S, and the sheet S that has passed through the nip portion 22c of the folding roller pair 22 falls until it contacts the regulation stopper 26, completing the switchback conveyance. Then (S11), the driving of the discharge roller motor 62 and folding roller motor 61 is stopped (S12). Here, the completion of the switchback conveyance of the sheet S may be determined by counting the number of driving pulses of the discharge roller motor 62 and the folding roller motor 61 and conveying the sheet S by a predetermined amount.

Next, the press guide motor 33 is driven to move the press guide member 30 to a position (reverse transport guide position) slightly projecting toward the sheet transport path 20 from the guide surface 21a (S13). At this time, the speed at which the pressure guide member 30 is returned from the guide position (see FIG. 14(c)) to the reverse transport guide position is set to a higher speed than when the pressure guide member 30 is moved from the retracted position to the guide position. there is When the pressing guide member 30 is moved from the retracted position to the guide position, it is rotated at a reduced speed in order to press and turn the stopped sheet S for switchback conveying, whereas it is rotated at the guide position. When moving from to the reverse transport guide position, the timing of executing the next operation can be advanced by returning quickly.

Next, the regulation stopper motor 63 is driven to move the second folding position of the sheet S to a position facing the folding blade 23 (S14). In this state, the cam motor 64, folding roller motor 61, and discharge roller motor 62 are driven to perform the second folding operation (S15-S17).

In this embodiment, motors for driving each member are separately provided, but it is also possible to drive each member by using a common motor and switching driving by means of a clutch or the like.

<Initialization control>
Next, the initialization control for positioning the pressing guide member 30, the pair of folding rollers 22, the aligning plates 28a and 28b, and the folding blade 23 at their respective home positions will be described with reference to the flow charts shown in FIGS. 25 and 26. FIG. The control unit 60 executes initialization control when the power of the sheet processing apparatus B is turned on or when a jam is cleared.

As shown in FIGS. 25 and 26, the control section 60 first determines whether or not the detection signal of the flag 90a is received from the optical sensor 90c of the pressure guide position detection unit 90 (S21). When the control unit 60 receives the detection signal from the optical sensor 90c, it means that the pressing guide member 30 is positioned at the retracted position, which is the home position. In this case, the control section 60 drives the folding roller motor 61 until the detection signal of the flag 91a1 is received from the optical sensor 91b of the folding roller position detection unit 91 (S22, S23, S24). As a result, the folding roller pair 22 rotates and moves to the home position.

On the other hand, in step S1, if the control unit 60 does not receive the detection signal of the flag 90a from the optical sensor 90c, the pressing guide member 30 is not positioned at the retracted position, and the sheet conveying path 20 including the guide position is not positioned. It means to be in any position. This state may occur, for example, when the sheet processing apparatus B is turned off during the folding process, or when a jam occurs. Therefore, the control unit 60 rotates the pressing guide motor 33 forward to rotate the pressing guide member 30 toward the retracted position (S25). After that, when the control unit 60 receives the detection signal of the flag 90a from the optical sensor 90c within a predetermined time after the pressure guide motor 33 is rotated forward, the control unit 60 stops driving the pressure guide motor 33 (S26, S27, S28). As a result, the pressing guide member 30 stops at the retracted position. After that, the control section 60 executes the above-described steps S22 to S24 to move the folding roller pair 22 to the home position.

Further, in step 27, when the control unit 60 does not receive the detection signal of the flag 90a from the optical sensor 90c within a predetermined time after the pressure guide motor 33 is rotated forward, the pressure guide member 30 interferes with the folding roller 22a. is assumed. That is, as shown in FIG. 27A, the folding roller 22 is not located at the home position, and the first roller surface 22a2 of the folding roller 22a is located on the locus of movement of the pressing guide member 30, and they interfere with each other. It is assumed that the rotation of the pressing guide member 30 is impeded.

A drive transmission mechanism (not shown) for transmitting the driving force of the pressing guide motor 33 to the rotating shaft 31 is provided with a torque limiter. Transmission of driving force to the pressing guide member 30 is cut off. Therefore, there is little possibility that the pressing guide motor 33 will press the folding roller 22a and both of them will be damaged. However, the pressing guide member 30 cannot be returned to the home position when the two interfere with each other.

Therefore, as shown in FIG. 27(b), the control unit 60 rotates the pressure guide motor 33 in reverse until the detection signal of the flag 90b is received from the optical sensor 90d, thereby moving the pressure guide member 30 to the guide position (S29). , S30, S31). Next, the control section 60 drives the folding roller motor 61 until the detection signal of the flag 91a1 is received from the optical sensor 91b of the folding roller position detection unit 91, thereby moving the folding roller pair 22 to the home position (S32, S33, S34). At this time, since the pressure guide member 30 is positioned at the guide position, it is not positioned on the rotational locus of the first roller surface 22a2 of the folding roller 22a, and the folding roller 22a reaches the home position without interfering with the pressure guide member 30. It can move (FIG. 28(a)).

Next, the control unit 60 rotates the pressing guide motor 33 forward until it receives the detection signal of the flag 90a from the optical sensor 90c (S35, S36, S37). At this time, since the pair of folding rollers 22 is positioned at the home position, the pressing guide member 30 can move to the home position without interfering with the folding rollers 22a. As a result, as shown in FIG. 28(b), the pressing guide member 30 moves to the retracted position, which is the home position.

In steps S30 and S36, if the detection signals of the flags 90a and 90b are not received from the optical sensors 90c and 90d within a predetermined time after the control unit 60 drives the pressing guide motor 33, the following is assumed. be. That is, it is assumed that the optical sensors 90c and 90d are out of order, or that the pressing guide member 30 bites into the first roller surface 22a2 of the folding roller 22a and cannot move. Therefore, in this case, the control unit 60 stops driving the pressing guide motor 33 and issues an error notification (S38, S39, S40, S41).

Here, the method of notifying the error is not particularly limited as long as it is a method that allows the user to recognize the error. That is, for example, an error message is displayed on the display of an operation panel (not shown) provided in the image forming apparatus A or the sheet processing apparatus B, which is operated by a user to set image formation and sheet processing. and a method of displaying an error on the display of an external device such as a personal computer connected via a network.

Next, the controller 60 drives the aligning plate motor 65 to move the aligning plates 28a and 28b to the home position until the aligning plate sensor 66 detects the aligning plates 28a and 28b (S42). Next, the control section 60 drives the cam motor 64 to move the folding blade 23 to the home position (S43). After that, the control unit 60 terminates the initialization control.

The reason why the folding blade 23 is moved to the home position last in the initialization control is as follows. That is, since the folding blade 23 reciprocates as the cam member 25 rotates, depending on the position of the folding blade 23 at the start of the initialization control, when the cam motor 64 is driven, the leading edge of the folding blade 23 moves toward the sheet stacking tray 21 . may move to the sheet conveying path 20 side from the guide surface 21a. In this case, if the folding roller pair 22 and the pressing guide member 30 are not positioned at the home position, the folding blade 23 may interfere with these members and be damaged. In order to suppress such damage, the movement of the folding blade 23 to the home position is performed at the end of the initialization control.

<Other embodiments>
Although the configuration in which the pressing guide member 30 is L-shaped has been described in the above-described embodiment, the present invention is not limited to this. That is, the shape of the pressing guide member 30 is not limited to the L-shape, and may be a rod-shaped member, for example.

In the above-described embodiment, the folding roller 22b has a circular outer peripheral first roller surface 22b2 with a constant outer diameter and a second roller surface 22b3 with a smaller outer diameter than the first roller surface 22b2. However, the folding roller 22b may be a roller having a constant outer diameter, such as a circular rubber roller, as long as it can form a nip portion by pressing against the first roller surface 22a2 of the folding roller 22a.

Further, in the above-described embodiment, the regulation stopper 26 is arranged at the lower end of the sheet stacking tray 21 to regulate the leading edge of the conveying direction of the conveyed sheet by contacting the regulation stopper 26 . shows an example in which it is provided so as to be able to move up and down along the sheet stacking tray 21 . In another embodiment, roller pairs for conveying sheets may be arranged on the upstream side and the downstream side in the sheet conveying direction with the folding blade 23 and the folding roller pair 22 of the sheet stacking tray 21 interposed therebetween. In this case, when the sheet S that has been subjected to the first folding process is conveyed in a switchback manner, the folding blade 23 and the pair of folding rollers 22 of the sheet stacking tray 21 are sandwiched between the upstream side and the downstream side in the sheet conveying direction. can also be returned to

20 Sheet transport path 21 Sheet stacking tray 21a Guide surface 22 Folding roller pair 22a Folding roller (first rotating body)
22a2... First roller surface (first peripheral surface)
22a3... Second roller surface (second peripheral surface)
22b... Folding roller (second rotor)
22c... Nip portion 30... Pressing guide member (guide member)
33... Pressing guide motor (first motor)
60... Control unit 61... Folding roller motor (second motor)
90a... Flag (first detector)
90b... Flag (third detector)
90c... Optical sensor (first detection unit)
90d... Optical sensor (third detection unit)
91 Roller position detection unit (second detection unit)
A... Image forming apparatus B... Sheet processing apparatus F... Folding processing apparatus

Claims (9)

In a sheet processing device that folds a sheet,
a conveying path having a guide surface for guiding the conveyed sheet;
a first rotating body having a first peripheral surface with a constant radius to the peripheral surface and a second peripheral surface with a radius smaller than the radius of the first peripheral surface;
A second rotating body that rotates in synchronization with the first rotating body and presses against the first peripheral surface of the first rotating body to form a nip portion, wherein the second rotating body is conveyed to the conveying path during the folding process. The folded sheet is conveyed in the first direction and subjected to the folding process by rotating while being sandwiched by the nip portion, and the folded sheet is rotated while being sandwiched by the nip portion. a second rotating body that is switched back and conveyed in a second direction opposite to the first direction;
contacting the sheet that has undergone the folding process in the conveying path and is being moved in the second direction by the nip portion, and one end of the sheet is positioned on the side of the conveying path where the other end of the sheet is positioned; a first position that is substantially flush with the guide surface or a position that is more retracted from the conveying path than the guide surface; and a first position that contacts the sheet in the conveying path. 2 positions, and when rotating from the first position to the second position, the rotation trajectory between the first circumferential surface and the second circumferential surface. a guide member that enters the area and contacts the sheet at the second position located outside the area;
A sheet processing apparatus comprising: a first detection unit that detects that the guide member is positioned at the first position;
a second detection unit that detects that the first rotating body is positioned at a position that does not contact the guide member positioned within the area;
A first motor for driving the guide member rotates in a first rotation direction to rotate the guide member from the second position to the first position, and rotates the guide member in a second rotation direction opposite to the first rotation direction. a first motor that rotates in a rotational direction to rotate the guide member from the first position to the second position;
a second motor that drives the first rotating body;
a control unit that controls the first motor and the second motor;
with
When the guide member positioned in the conveying path is moved to the first position, the control section rotates the first motor in the first rotation direction and then rotates the first detection section within a predetermined time. does not detect that the guide member is positioned at the first position, the first motor is rotated in the second rotation direction, and the first rotating body is positioned at the non-contact position by the second detection unit. 2. The sheet processing apparatus according to claim 1, further comprising a mode in which said first motor is rotated in said first rotation direction after said second motor is rotated until it is detected that the first motor is rotated. A third detection unit that detects that the guide member is positioned at the second position,
In the mode, the control unit prevents the first detection unit from detecting that the guide member is positioned at the first position within a predetermined time after the first motor is rotated in the first rotation direction. In this case, the first motor is rotated in the second rotation direction until the third detection section detects that the guide member is positioned at the second position, and the second detection section detects that the first rotor is rotated. 3. The sheet processing according to claim 2, wherein the first motor is rotated in the first rotation direction after the second motor is rotated until it is detected that the contact is located at the non-contact position. Device. The third detection unit has a flag that rotates in synchronization with the guide member, and an optical sensor that detects the flag when the guide member is positioned at the second position,
When the guide member rotates from the second position to the first position, the flag abuts against a restricting portion that restricts rotation of the flag, thereby preventing the guide member from being positioned at the first position. 4. The sheet processing apparatus according to claim 3, wherein: In the mode, the control unit prevents the third detection unit from detecting that the guide member is positioned at the second position within a predetermined time after the first motor is rotated in the second rotation direction. 5. The sheet processing apparatus according to claim 3, wherein an error is notified when the error occurs. When moving the guide member positioned at the first position to the second position, the control section rotates the first motor in the second rotation direction and then rotates the third detection section within a predetermined time. 6. The sheet processing apparatus according to claim 3, wherein the driving of the second motor is stopped when it is not detected that the guide member is positioned at the second position. The controller controls the first motor and the first motor so that the guide member is positioned at the first position and the first rotating body is positioned at the non-contact position when the sheet processing apparatus is powered on. 7. The sheet processing apparatus according to claim 2, wherein the second motor is controlled. 8. The sheet processing apparatus according to any one of claims 1 to 7, wherein the sheet processing device folds the sheet at a plurality of locations such that the one end portion of the sheet is positioned inside the folded sheet. A sheet processing apparatus according to any one of the preceding items. an image forming apparatus that forms an image on a sheet;
The sheet processing apparatus according to any one of claims 1 to 8, wherein the sheet fed from the image forming apparatus is folded.
An image forming system comprising:

Images